Augmented reality (AR) technology is known in which, when displaying an image which is obtained by capturing the real world on a display, by displaying content which is not present in the real world superimposed on the image which is displayed on the display, a composite image in which the content appears to be present in the real world is provided. Hereinafter, the content will be referred to as AR content.
A user viewing the composite image may acquire information which is displayed as AR content, and may ascertain more information in comparison with a case in which the real world is observed directly. Note that, due to the shape, color, or the like of the AR content itself, the AR content may be image data which causes the recollection of a characteristic meaning, image data containing textual data, or the like.
AR includes technology referred to as location-based AR and technology referred to as vision-based AR. In location-based AR, positional information and information relating to the direction of a camera-equipped terminal is acquired from a GPS sensor or the like, and the AR content to be displayed in a superimposed manner, the position at which to display the AR content in a superimposed manner, and the like are determined according to the positional information, the information relating to the direction, and the like. The AR content is displayed superimposed on the image which is captured by the camera.
In vision-based AR, the image data which is acquired from the camera is subjected to object recognition and spatial recognition. In vision-based AR, when it is recognized that the image data is the data of an image in which a specific object is captured, AR content corresponding to the specific object is displayed in a superimposed manner according to the result of the spatial recognition (for example, patent literature 1 and patent literature 2). Note that, it is referred to as marker-type vision-based AR when a marker is used as a recognition target, and it is referred to as markerless-type vision-based AR when an object other than a marker is used as the recognition target.
Here, description will be given of an outline of the process flow in vision-based AR technology of the related art. FIG. 1 is a diagram illustrating an outline of the process flow in vision-based AR technology of the related art. Note that, an AR processing program of the related art is installed on a computer, and the vision-based AR of the related art is realized by the computer executing the AR processing program.
The computer activates the AR processing program according to input from a user or the like (Op. 100). The following AR processes are executed by the computer activating and executing the AR processing program. The computer which is executing the AR processing program transmits a camera activation command to the application which controls the camera in order to capture an image of the processing target (Op. 101). Accordingly, the camera is activated, and the capture process which is performed by the camera is started.
Next, the computer acquires the image data from the camera (Op. 102). By executing the image recognition, the computer determines whether a specific object is contained in the acquired image data (Op. 103). When the marker-type vision-based AR is used, it is determined whether image data indicating a marker is contained in the captured image data.
When the specific object is contained in the image data (yes in Op. 103), the computer executes a process for displaying AR content according to the specific object to be superimposed on the image data (Op. 104). For example, as described above, the position at which to superimpose the AR content is determined according to the results of the object recognition and the spatial recognition, and the AR content is displayed to be superimposed in the determined position. Note that, when the specific object is not contained in the image data (no in Op. 103), the process proceeds to Op. 105 without executing Op. 104.
The computer determines whether or not to end the AR processing program (Op. 105). When the AR processing program is not ended (no in Op. 105), the processes of Op. 102 onward are repeated. Meanwhile, when the AR processing program is ended (yes in Op. 105), the computer stops the capture process which is performed by the camera by transmitting a camera stop command to the application which controls the camera (Op. 106). The computer ends the AR processing program (Op. 107). These techniques are disclosed in Japanese Laid-open Patent Publication No. 2002-092647, and Japanese Laid-open Patent Publication No. 2004-048674, for example.